async
已弃用: use waitForAsync(), (expected removal in v12)
改用 waitForAsync()（将在 v12 中删除）
async(fn: Function): (done: any) => any
改用 waitForAsync()（将在 v12 中删除）
Deprecated use waitForAsync(), (expected removal in v12)
参数
fn | Function |
返回值
(done: any) => any
